The number of patterns of non-papaya words.

Terms

a(0) =0a(1) =0a(2) =1a(3) =5a(4) =31a(5) =153a(6) =778a(7) =3890a(8) =20693a(9) =114733a(10) =676347a(11) =4207203a(12) =27633048a(13) =190864320a(14) =1382896511a(15) =10479940137a(16) =82864510321a(17) =682075572641